Method of and apparatus for removing the insulation from electrical conductors



Feb. 10. 1925. 1,526,063

J. T. GRlFFlN ET AL METHOD OF AND APPARATUS FOR REMOVING THE INSULATION FROM ELECTRICAL CONDUCTORS Filed Dec. 16, 1920 3 Sheets-Sheet 1 James]? Gm fm 44 [1677219. 1772772 Feb. 10. 1925. 1,526,063

J. T. GRIFFIN AL METHOD OF AND APPARATUS FOR REMOVIN HE INSULATION FROM ELECTR c L DUCTORS Filed. c. 1920 15 Sheets-Sheet 2 l l l 5 9 fnflenfirs lmesl". Gmffln Mllzam 11234221722 Feb. 10. 1 25. 1,526,063

J. T. GRIFFIN ET AL METHOD OF AND APPARATUS FOR REMOVING THE INSULATION FROM ELECTRICAL CONDUGTORS Filed Dec. 16 1920, 3 Sheets-Sheet 5 fizz/9717075 James]? Grzffl'n Mil/am fl. Hmm

l atented Feb. 10, 1925.

stares r. ennrin, assrenons ro NEW YORK.

LATION FROM ELECTRICAL CONDUCTORS.

Application fi led December 16, 1920. Serial No. 431,189.

To all whom it may concern:

Be it known that we, James T. Gnmrm and. WILLIAM A. TIMM, citizens of the United States, residing at Oak Park and 5 Bcrwyn, respectively, in the county of Cook and State. of Illinois, have invented certain new and useful Improvements in Methods of and Apparatus for Removing the Insulation from Electrical Conductors, of which the followingis a full, clear, concise, and exact description. I

his invention relates to an improved method of and apparatus for removing the insulation from electrical conductors, and more particularly to conductors which are coated with an insulating compound and covered with a textile covering.

it is one of the objects of this invention to provide an eilicient method or" and convenient apparatus for rapidly removing the textile coverings and the insulating compound from the conductor in a single operation without removing or harming a tin coating which may be applied thereto and without burning or charring the textile coverings.

The steps of a method practice of this invention consist essentially in severing by pressure the textile coverings, applying heat to the insulating compound to cause a flow of it, and stripping the sev cred portions of textile coverings and the the conductor.

softened compound from The stripping operation is in-a direction longitudinally or" the conductor.

A convenient apparatus for practicing the above method and embodyin features of this invention comprises a pair or" oppositely disposed pivotal jaws of when pressure is applied and equipped with heating means for raising the jaws to a temperature sutficient to soften the insulating compound.

As a further feature of this invention, means are provided for mounting the heating elements in the jaws in such a manner that they may be readily removed for re placement and repairs.

Another to a compact and convenient form of portmay be connected employed in the.

sutlicient hardness? and strength to sever the textile covering objecf of this invention relatesable container for the skinning tool and its associated apparatus whereby the apparatus directly with a commer cial circuit by the mere insertion of the plug and all adjustable and replaceable parts will be readily accessible for operation and maintenance.

A form of container suitable for this purpose is one in which a compartment is provided for enclosing a transformer which is connected by leads to the apparatus and to a connecting plug, the skinning apparatus and plug with their leads being coiled in a shallow portion in the top of the container when not in use. Compartments provided in the front of the container and covered y a convenient door contain a regulating switch and fuses respectively. The compartment containing the fuses may also have a screw plug adapted for use in the socket of a commercial circuit.

In the drawings:

Fig. 1 is a perspective view of the electrically heated skinning tool shown as used in the method-oi preparing the wires of switchboard cables for soldering to the terminals;

2 is an enlarged side view section of the j aw end of the tool;

3 is aperspective view showing the assembly of the flaw covering member with partly in the heating element the conductor connection;

i is a vertical section taken on the line H of Fig. 2;

Fig. 5 is a vertical section taken on the me 5-5.05 2;

Fig. 6 is a a tial end view looking LO ward the right or Edi 2;

is a cross section of one type of insulated wire which is ada ted to have the insnlation removed therefrom by the method and apparatus of this invent'on;

8 is a plan viewci the transformer and tool container. with the cover thereof partly broken away;

Fig. 9 is a front view thereof with the switch and fuse compartment uncovered and the cover therefor partly broken away; Fig. 10 is a plan section taken on the line i( 10 of Fig. 9, and

lOO

ard make mainly modified to enclose a.- heat ing element 16 inthe form of a resistance ribbon placed in each jaw 17 thereof and preferably equipped with wooden handles,

18 suitably secured to metal handle portions 19 of the pliers 15. A shallow channel 23 formed in the gripping face of each jaw 17,. best shown in lgs. 2 and 5, ex-

, tends a short distance from the end thereof to a point near-the pivotal connection 24 of the jawsand encloses the heating element 1.6 A U-shaped square-cornered metallic cover member" 25 surrounds three sides of each jaw 17 including the gripping face,

thereby forming a closure for thegrhannel 23 and extending along the sides of the jaw for approximately ,threeuarters of its length. Pins 26, 26 suita ly spaced and secured tothe sides of the jaw 17 enter suit-- able openings in the cover member 25 to hold it in place and still allow for its re-- moval when necessary, as will be explained further on in the-description; In modify ing the pliers 15 for use in this invention thegripping faces of the jaws 17 are cut. down to the thickness of the material forming the cover member 25 so that the jaws 17 will have a suitable gripping and severing effect on the wire conductors placed therebetween in the use of this invention. At its inside end the channel 23 is enlarged, as indicated at 27, to' extend towardone side with the direction of enlargement reversed in each jaw.17. The enlargement- 27 in the channel 23 is semi-cylindrical in shape and extends deeper into the jaw than the main channel. Projecting into the en'- largement-27 is a connector and supporting {in 29 to which is brazed one end of the eating element 16. The other end ofthe heating element is adapted to be secured,

preferably by brazing, to the cover 25 .with

the length between the two connecting points spaced from contact with the jaw 17 and the cover 25. Suitable layers 30 of insulation, preferably mica, the width ofthe channel 23, are secured to the inside face of the cover 25 which encloses the channel 23 and to the su face of the channel 23 above the-heating e ement 16 to provide against 1 I thecover 25, making contact with the heating element in case undue manipulation of the pliers should force the cover 25 into the channel 23, or if the heating element should the surfaie abovethe channel 23. The space around the pin 29 between 'it and the enlargement 27 in the channel 23 is filled with a suitable insulation, preferably asbestos string, as indicated at 31. The pin 29 is secured a? a conductor plate '32 which is shaped to follow the shapexof the jaw member 17 from the jawportion of the oiiset handle portion 19 where it is secured by bolts'33 to a conductor strip 34 which is positioned along one'side of the handle portion 19 of the pliers and suitably insulated therefrom by a layer of tape as indicated at 35. The conductor plate 32 is spaced from contact, with the jaw 17 about its central portion by a wrapping of some suitable insulation such as tape, indicated at 35. One side of the circuit is suitably connected to the conductor strip 34: with the other side thereof connected direct to the handle por tion 19 by-a conductor strip 36 suitably secured, preferably by brazing, to the opposlte side thereof. The wooden handle members 18 are channeled out as indicated at 40, best shown inflFi'g. 6, and within them the bandle portion 19 of the pliers withthe conductor strips 34 and 36 are secured by means of screws '41 suitably positioned along and threaded into the handle portion 19. Layers 42 and 43 of suitable insulation are secured within the channel4O to'insulat'e the metal handle portion 19 and the conductor strip plate 32. A leaf spring 45'.is positioned between the handles 19, being suitably secured to one handle and resting against the other, thereby tending to force the j aws, 17 apart.

I .To facilitate a quick repair of the skinning tool in case the heating element burns out or should not function properly the conductor plate 32 with the pin 29 which has secured to it one end of the heating element 16, the other end of which is secured to the cover member 25, are all adapted to be removed frem the jaw as one unit and quickly replaced with a new one. When this change 33 whereby the nuts'thereof may be removed to allow for the removal of the conductor is necessary the nuts are first removed from i the bolts 33 and the plate 32 free therefrom. The sides of the cover 25 are now pried from the sides of the jaws a suflicient. distance to clear the pins 26 secured thereto, after which by turning the unit with the pin '29- as its axis within the enlarged por tion 27 of the channel 23 in a direction to clear the top edge of the sides of the cover 25-from the inside surface of the jaw and then moving it sideways to free'the pin 29 from the 'enlar ement 27 of the channel 23, the unit may e removed and in the j I I reverse order a new unit substituted;

become bowedenough to make contact with This feature "of the quick removal and replacement of the heating element with its supports provides for a very efficient tool,

. transformer 48 delivers element 16. The conductor 49 and a con-' ductor 50 of suitable length which connects the secondary of the transformer with the skinning tool are all housed within an u per compartment 51 of the case 47. Within a compartment 52 located below the compartment 51 and at one side of the case are suitable fuses 53 which are connected 1n the line between the source of current and the primary side of the transformer to protect it in case the conductor 49 should be plugged in on a direct current line or in case of as ort circuit in the skinning tool. A. switch 55 for regulating the voltage delivered to the Secondary is connected to the primary slde of the transformer and is conveniently mounted in the compartment 52. In the electrical circuit illustrated in F g.

11, 60 denotes an alternating current generator connected to the primary side of the transformer 48 with the fuses 53 connected in the lines therebetween. The switch 55 for regulating the'voltage delivered to the secondary of the transformer isillustrated in the conventional way. The heating elements 16 are connected in parallel to the secondary side of the transformer as illustrated.

In the use of this tool, which is illustrated in Fig. 1, as applied to skinningthe ends of the wires of sw1tchboard cables preparatory to being soldered to terminals, the wires (see Fig. 7) are of copper with first a coating oftin 60, then a-coating of black enamel 61, and then two 1 servings of textile insulation 62 applied thereto.

In using the tool the gripping surfaces of the jaws 17 are first brought to a suitable temperature by regulating the switch 55, and then the operator, as illustrated, ips the conductor between the jaws 17 an applies a suitable pressure. to sever the cover-' ings and at the same time melt the 1118111819 1ng compound coating by action of the heated surfacesof the jaws. In applying the pressure there will be a give or very slight drop of the jaws at the completion of the severing which will notify the operator of the giving away of the textile. Upon the above notification the operator will release the pressure a trifle and imm iately apply a movement sideways on the tool toward the end of the conductor. This last movement will cause the severed covering to compound coating which causes it to an example of I uickly move off the wire with the insulating compound melting, due to the heated gripping surfaces of the jaws. The severing of the covering is so quick that the textile coverings are not burned or charred by the heat of the grippin surfaces of the jaws, but this heat'is su cient to melt the insulat-iigg taken off without harming the tinned sur face of the wire.

The temperature of the heating elements "may be' so regulated that the jaws'will not .besutliciently hot to burn or char the textile pcovering but will be raised to a' sufficiently high temperature to melt or flow the insulatl'ngcompound.

What is claimed is:

1. Themethod of removing the insulation from conductors coated with an insulating compound and covered with a textile covermg,- which consists in applying pressure and heat to sever the textile covering and melt the insulating compound and removing the insulation by a stripping action.

2. The method of removing the insulation from conductors coated with compound and covered with a textile cover-' mg, which consists in applying pressure to sever the textile covering and heat to melt the insulating compound and finally removing the insulation from the conductor by a relative longitudinal movement of the conductor and the insulation.

3. The method of removing insulation from conductors coated with an insulating compound and covered with a textile cover- 1ng which consists in the simultaneous application of heat and pressure to the insulation to severthe continuity of the textile covering and melt the insulating compound and finally stripping the severed portion of textile and the melted portion of the compound from the conductor by moving it ongitudinally thereof.

4. The method of removing insulation from the ends of conductors coated with an insulating compound and covered with a textile covering, which consists in applying pressure to the covering to sever it and simultaneously applying heat at the pont under pressure to melt the insulating com-' pound, and finally skinning the severed coverings including the melted insulating compound from the wire in one operation.

- 5. The 'met-hod of removing insulation from the ends of conductors coated with an insulating compound and covered with a textile covering, which consists in applying pressure to the-covering to sever it and si multaneously applying heat along the surface under pressure to melt the insulating compound, and finally by a continued pres sure and a movement 0 the severed covering in a direction longitudinally of the wire skinning the severed coverings including the an insulating sulation material'from conductors, compris-' ing a pair ofoppositely disposed jaw members,'heating means associated with each of said jaw members and carriedthereby.

8. A hand operated tool for stripping insulation material from conductors, comprisa pair of oppositely disposed jaws prov1 e d in their gripping face with a chamber,

an exchan eableand replaceable electrical heating umt for each jaw supported within the chamber, and means for supplying current to said heating units to heat said jaws.

9. A hand operated tool forstripping insulation material from'eonductors, a pair of oppositel disposedpivotal jaws, a resstor' associate with each of said jaws, and means for su plying current to said resistors to heat sa d aws.

10. A hand: operated tool for stripping insulating material from conductors, a pair of oppositely disposed pivoted jaws, an electrically operated heating element associated with each of said jaws, handle members for operating the jaws, andelectrical connections for said heating elements supported by the handle members.

11. A hand operated tool forstripping insulating material from conductors, a pair of oppositely disposed pivotal jaws, an electrically operated heating element removably mounted oneach ,of, said jaws, andhandle members for operating said jaws.

12. An a paratus comprising oppositely disposed, pivoted, and heated jaws for simultaneously removing in a single operation a textile covering and an insulating compound coating from. a coated and textile covered conductor.

13. An apparatus for removing an insulating compound coat ng and a textile covering from a coated and textile covered 'conductor comprising compressible, heated members for severing the textile covering and melting the coating of insulating compound. I

14. In an apparatus for stripping an insulating compound and a textile covering from conductors coated with, a compound andcovered with a textile covering, a pair of compressible jaws adapted to sever the textile covering, and heating elements applied to said jaws for maintaining them at atemperature to melt the insulating compound. j

15. A hand tool for skinning textile coverings and insulating compound coatings from the ends of coated and textile covered conductors, comprising compressible jaw members adapted upon operation to compress the covering to sever it, and means for heating said jaw members for simultaneously causing the insulating compound coating to melt.

A hand tool for skinning textile cova erlngs and insulating compound coatings i from the ends of coated and textile covered conductors, comprising compressible flat faced gripping jaws adapted upon operation a to compress the covering to sever it, and

electric heating means associated therewith for simultaneously causing the insulating compoundqoating to melt. r

17. A hand tool for skinning textile coverings and insulating compound coatings from the ends of coated and textile covered conductors, comprising pivoted gripping jaws adapted upon operation to compress the covering to sever it, and electric heating means associated therewith for simultaneously causing the insulating compound coating to melt.

18. A hand tool for skinning textile coverings and insulating compound coatings from the ends of coated and textile covered conductors, comprising compressible flat faced jaw members adapted upon operation to'compress the covering causim it to he severed, an electric heating element within each jaw member for simultaneously melting the insulating compound coating, and electric circuit connections for said electric heating elements carried on said jaw members.

19. A hand tool for skinning textile coverings and insulating compound coatings from the ends of coated and textile covered conductors, comprising compressible flat faced gripping jaws each provided with a chamber for housing an electric heating element comprising a resistance ribbon, said jaw members adapted upon operation to compress the covering causing it to be severed while simultaneously the heat radiated from said resistance ribbon melts the insulating compound coating, and electric circuit connections for said resistance ribbon carried on said jaw members. 7

20. An electrically heated hand tool for skinning textile coverings and insulating ,com ound coatings from the'ends of insula conductors, compressible grippin jaws provided in their gripping face wit a chamber, handles for sai jaws, an exchangeable and replaceable electric heating unit for each jaw comprising a resistance ribbon adapted to be supported within the chamber, a cover member for the chamber adapted to form the gripping face of the jaw and to support one end of said resistance ribbon, a circuitconnecting and supporting member for the other end of said resistance ribbon mounted on each of said handles, means for mountin said cover members on said jaws and sai circuit connecting and supporting members on said handles to support said resistance ribbons in position whereby they may be readily removed and replaced, said jaws adapted upon operation to compress the it to be severed while simultaneously the heat radiated from said resistance ribbon melts the insulating compound coating, and

electric circuit connections for said circuit connecting members carried on said handles.

15 former,

21. A portable wire stripping apparatus comprising a heated stripping tool, a transcircuit controlling apparatus, and

covering causingcircuit connections between said stripping tool, transformer and circuit controlling apparatus.

22. A portable wire stripping apparatus comprising an electrically heated hand stripping tool, a transformer, protective apparatus, circuit controlling apparatus, and

electrical connections between said stripping tool, transformer, protective apparatus and circuit controlling apparatus.

In witness whereof, we hereunto subscribe our names this 6th day of December A. D.',

JAMES. T. GRIFFIN. WILLIAM A. TIMM, 

